Electric contact



May 15, 1928. 1,669,653

w. E. CAMPBELL ELECTRIC CONTACT Filed Nov. 16, 1925 afrozueq Patented May UNITED STATES WILLIAM E. camrnnnn, or urban, mnmnso'rn.

ELECTRIC CONTACT.

Application filed November 13, 1925. Serial No. 68,777.

This invention relates to electric contacts and has special reference to one having a roa tary element. therein whereby a constant,

niform, and positive contact is assured.

The present embodiment of the invention is particularly designed for association with electric condensers, variometers, or variocou- I .plers, or the like, and, while the same illustrates a specific construction and adaptation,

it is to be understood that various modifica A tions within the scope of the appended claims may be resorted to without departing from the spirit of the invention.

. The principal object is that of producing a moreeflicient and dependable contact of the character described than heretofore known.

Another object is to produce as noiseless a contact of this character as possible, especially when used in connection with radio ap aratus.

ther objects and advantages of the invention will appear in the further description thereof.

Referring now to the accompanying drawing, formin part of this application, and in which 1i e reference characters indicate like parts:

Figure 1 is a vertical sectional view through one of the improved contacts as applied to a variable condenser; and

Figure 2 is a modified form showing the invention as applied to avariocoupler.

In Figure 1, 1 represents the armature shaft of the condenser and '2 the se ments that are carried thereupon in such evices. 3 and 4 represent the male and female members respectivel of the circular housing about the end 0 the shaft 1, the male member 3 having formed axially thereof the elongated hub 5 which forms a bearing for the shaft 1,-the latter being reduced in diameter.

at this point, providing shoulders at either end of such reduced portion, the outermost shoulder being the inner wall of the disc 6 which is formed integrally with the shaft. This disc 6 is slightly less in diameter than the inside measurement of the male member 3, and is disposed normally centrally of the housing formed by the members 3 and,4.'

Centrally of and in the inner wall of the member 4 1s formed a concaved recess 7 into which protrudes the pointed end 8 of the shaft 1, however there being'no hearing at such extremi of the shaft, the depression 7 being simp y for the reception of sulficient of the fluid 9, in the event the condenser is operated with the shaft 1 in vertical po sition, to insure a constant contact intermediate of the housing and the shaft, and-this depression or pocket 7 may be made larger than illustrated, if so desired.

The liquid 9 is preferably mercury and is contained with the housing formed by the members 3 and 4, so that some portion of the disc is at all timessubmerged therein. I The entire housing about the shaft isxpreferably incased withm a non-conductor, such as bakelite, or the like, as at 10, through which one terminal 11 is installed While the opposite terminal of the socket is shown at 12, it extending through the bakelite to the female member 4 of the housing, thus insuring a constant and positive contact for the circuit. I

In Figure 2 is illustrated a modified form of like contact as applied to a variocoupler, the shaft thereof appearing at 13, it having formed integrally therewith the circular disc '14, occurring within the housing formed by the'male and female members 15 and 16 respectively they together forming the bearing for the shaft 13 as it extends wholly throu h the housing, and in which event both t a male and female members 15 and 16 are provided with slightly elongated hub portions 17 and 18 respectively forming thrust bearings for thedisc 14. 1 a v Within the housing thus formed is placed the mercury or other conducting fluid 18,

which, as is obvious, establishes a constant contact between the disc andthe housing, the terminal of the .electric circuit being shown at 1 9 as occurring in the male member 15 of the housing.

From the foregoing it is evident that I have produced an exceedingly sim 1e and constant contact adaptable to many ifierent electrical devices.

Having-thus dsecribed my invention, what I claim and desire to secure by Letters Patwithin "the housing normally t housing andmunication intermediate of shaft when the latter is operated while iii 'a'" horizontal position, and cooperable means carried by the shaft and housing for main- .the terminal, a circuit conducting liquid taining such closed relation when the shaft is operated while in a vertical position.

2. The combination witha circuit conducting rotary shaft having a circular ter- 5 minal thereabout, said shaft being movable from a horizontal to a; vertical position, a

, chamber within which the terminal rotates,

and a liquid electrolytewithin the chamber,

of means projecting from the terminal whereby the electrolyte is in constant con- 1. tact therewith whether the shaft is disposed vertically or horizontally.

In testimony whereof I hereunt0 aflix my signature.

WILLIAM. E, CAMPBELL. 

